Broaching machine



May 8, 1928.

o. J. DANSEREAU BROACHING MACHINE Filed June 8. 1921 2 Sheets-Sheet 1 May 8, 1928.

o. J. DANS'EREAU BROACHING MACHINE Patented May 8, 1928.

' UNITED STATES PATENT ornce.

OMEB J. DANSEREAU, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR 'I'O SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

BBOACHING MACHINE.

Application filed .Tune 8 My invention relates to broaching machines. 4

An object of my invention is to provide an improved broaching machine. Anotherv 6 object of m invention is to provide a reversible or ouble-acting broaching machine. A further object of my invention is to provide an improved broaching machine for simultaneously applying power acting in the 1 same direction to the opposite ends of the broach. A still further object of my invention is to rovide an improvedbroaching machine in hich power 1s simultaneously applied to the opposite ends of the broach to move it in one direction and the power so applied is automatically transmitted substantially equally to the opposite ends of the broach. Other objects of my invention andcertain advantages thereof will appear in the course of the accompanying specification and the appended claims.

In the accompanying drawings I have shown for purposes of illustration one embodiment which my invention may assume 2 in practice.

In these drawings,-. Fig. 1 is a plan view of the illustrative form of my improvedbroaching mechanism. Fig. 2 1s a central vertical longitudinal section through my improved broaching mechanism upon line 22 of Fig. 1.

Fig. 3 is a transverse section on the line as of Fig. 2.

Fig. 4 is a transverse section through a portion of the controlling mechanism on the plane of the line 44 of Fig. 1.

Fig. 5 is a view similar to Fig. 4 taken on the line 5-5 of Fig. 1.

Fig. 6 is a diagrammatic view of my-improved broaching mechanism.

Fig. 7 is a detail in elevation showing the means cooperating with the broach in the holding thereof. l Fig. 8 is a modified form ofcylinder and 4 piston construct-ion.

It is a well known fact that many broaches are broken in practice by reason of the heavy strain which must be imposed upon them and the difficulty in properly tempering them. It is evident that if these broaches could be subjected in some manner to the necessary force for causing them to effect a broaching operation in such manner as to avoid either an excessive tension or an 1921. SeI'iaI NO. 475,893.

excessive com ression, the breakage of broaches woul be greatly reduced and the entire broaching operation facilitated. It is clear 'that if the necessary force could be equally divided between a push and a pull, this desirable condition would be substantially obtained. It is further evident that if power could be applied to the opposite ends of the broach so as to simultaneousl pull upon the forward end thereof and pus upon the rearward end, it would be very desirable to so proportion or distribute the power that the push and pull would be automatically maintained in the proper ratio to keep the braking strain upon the broach at a minimum. It is further obvious that it would be highly desirable to render it possible to avoid making the broachin machine run idly in either direction, an thereby largely increase the output of the broaching machine. These results, it will be evident from the following description are accomplished by my improved mechanism.

In the illustrative form of my invention, it comprises a hollow base casting 1 containing a chamber 2 which serves as a combined oil or other liquid reservoir, and mounted at the opposite ends of the casting or frame are coaxial cylinder members 3 and 4, these cylinder members being provided with pistons 5 and 6 respectively, which are reoiprocable in the cylinders under the action of a suitable liquid, for example oil, pressure applied alternately on the opposite sides thereof. For the purpose of causing the pistons 5 and 6 to reciprocate simultaneously in the same 90 direction, a connection 7 communicating by short pieces of pipe 8 and 9 with the bores of the cylinders 3 and 4 is made between the, left hand ends of cylinders 3 and 4. A similar connection 10 communicating by short pipes 11 and 12 with the bores of the cylinders 3 and 4 connects the right hand ends of the cylinders. Within the frame 1 is a liquid reservoir as previously described. From this reservoir a suitable pump 15 draws liquid by way of a connection 14 and discharges it through a line 16 to the 4-way valve casing 17. The line 16 comprises not only a branch 18 leading to the valve 17, but a branch 19 leading to'an adjustable pressure relief valve 20 and beyond this valve to a line 21 which returns to the oil chamber. The valve casing 17 communicates by short pipes 22 and 3 and oil chamber 2, while a pipe 2 allows communication between the left end of cylinder 4 and the oil chamber 2; Stop valves 3 and 4 are also disposed in the pipes 21 and 2. A suitable pressure gauge 24 is arranged upon the line 18 to permit the pressure acting in the system to be observed and to aid in the adjustment of the pressure relief valve 20. Suitable stop valves, similar to the valves 3 and 4 and numbered 25, 26, 27, and 28, respectively, control the connections extending between the connections 23 and 22 and the left hand end of the right hand cylinder, left hand end of the left hand cylinder, the right hand end of the right hand cylinder, and the right hand-end of the left hand cylinder. Disposed mid-way between the cylindersis a supporting frame 30 upon which is mounted a perforated abut-- ment member 31 against which the blank to be broached, indicated at 32 in Fig. 2, may be supported. The pistons 5 and 6 are provided with piston rods 33 and 34, respectively, which at their adjacent ends are provided with socket members 35 and 36. In these socket members are secured auxiliary broach receiving members 37 and 38 (best seen in Fig. 7). The members 37 and 38 are bored out longitudinally/to receive the end of a broach and transversely slotted as indicated at 39 and 40 to permit the insertion of a key 41 (Fig. 2) by which the broach may be drawn in either direction and to cooperate with mechanism for the rear end of the broach. A center 44 having a shank 45 suitably shaped to fit the sockets in the members 37 and 38 is provided, this member having a collar 46 thereon to regulate the distance it seats in the sockets in the members 37 and 38. A broach B is positioned between the center member 44 and one or the other of the socket members 37 and 38.

From the foregoing description the mode of operation of my improved mechanism will be readily apparent. Assuming the broach in the position shown in Fig. 2 and the parts as indicated in that figure, the 4way valve 17 occupyin a position at 90 from that indicated in *ig. 6, and the pump running: then a liquid pressure from the pump 15 will be discharged to the left hand ends of the cylinders 3 and 4 and acting upon the pistons 5 and 6 will cause the broach to be simultaneously pulled and forced through the work piece 32 which is in position against the abutment member 31. When the broach has passed entirely through the work piece, the valve 17 will be shifted clockwise from its former position to a position 45 in a counter-clockwise direction from its position as shown in Fig. 6. This will result in the equal.

stopping of the supply of any further pressure to either end of the cylinders 3 and" 4 and the discharge of the pump will pass wholly back to the oil chamber. At this point, it should be noticed, however, that the possible travel of the piston 5 is greater than that of the piston 6 from the position shown in F i 2, and, accordingly, it will be noted that t e piston 5 will travel in such manner, after the piston 6 reaches the inner end of its cylinder, as to cause the broach to be drawn beyond the end of-the center 44. It will then be readily possible to withdraw the key 41 and remove the broach. To

cause the broach to make the opposite pass,

the center 44 will be withdrawn from the socket member 38 and inserted in the socket member 37. A work piece having been placed over the smaller end of the broach, the broach will have its smaller end passed through the'perforated abutment member 31 and be keyed by the key 41 inserted through the slot 40 to the member 38. Upon movement of the valve 17 to a position corresponding to that shown in Fi 6, the pressure fluid will be supplied to oth cylinder 3 and cylinder 4 at the right hand ends thereof. As a result, the istons 5 and 6 will begin to move to the le t, but by reason of the fact that the volume to the right of piston 6 is increased only as work is done, that is, as the broach is pulled through the work piece, piston 5 will travel more rapidly than piston 6 and so will promptly, due to its free movement, catch up to the broach, and the center 44 will engage the conical seat in the end of the broach, the broach being held. in suitable position for this purpose by the operator. Thereafter the power applied in moving the broach toward .the left will be substantially equally supplied by the pistons 5 and 6, the push being a little larger. than the pull by reason of the slight difference in area due to the piston rod 34. A very important result will banoted to rise from the fact that the power medium is supplied through a common pipe to the two plstons, and it will be evident that the pressure exerted by this fluid will be automatically divided in such manner that the work done will be substantially equally the result of theforces applied in each cylinder.

It will further be noted that in single acting broaches, the cylinder diameter of the pulling cylinder will be slightly increased so as to make the effective areas of the pistons Also, when space will permit, suitably packed tail rods 50, as shown in Fig. 8, equal in diameter to the piston rods 33 and 34 ma be used and so the push and pull absolute y equally divided in double acting machines.

While I have in this application specifically described one preferred form and a ans modification thereof which my invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the same ma be embodied in various other forms wit out departing from its spirit or the scope of the appended claims.

What I claim as new} and desire to scour by Letters Patent is r 1. A broaching machine comprising a broach for doing a unit of work, and means when normally operative adapted to subject said'broach to a working stress less than the total force required for performing said unit of work including means for placing a portion of said broach under compression and another portion thereof under tension during its working stroke, and to automatically maintain the same substantially equal when performing said unit of work.

2. A broaching machine comprising a broach for doing a unit-of work, and actuating means for said broach including hydraulic means adapted to subject the same to a working stress less than that required for performing said unit of work and to automatically maintain the same substantially equal, said actuating means includin means for placing a portion of said broac under compression and, another portion thereof under tension during its working stroke.

3. A broaching machine comprising a broach for doing a unit of work, and means adapted to automatically maintain asubstantially uniform working stress in said broach throughout its length less than the total force required for performing said unit of Work including means for placlng a portion of said broach under compression and another portion thereof under tension during its working stroke;

'4. A broaching machine comprising a broach, and means ada ted to automaticallyv maintain a substantial y uniform working stress throughout substantially the entire length of said broach during its entire working stroke.

5. A broaching machine comprising a br ach, and means for simultaneously subjecting the same to compression and tension stresses, and to automaticall maintain the same substantially equal t roughout the working stroke of the broach.

6. A machine tool having a longitudinal cutter bar for doing a unlt of work, and

means for subjecting said bar to a Working stress less than the total force required to perform said unit of work and to automatically maintain the same substantiallv equal during the entire operation thereof including means for placing a portion of said cutter bar under compression and another por-- -tion thereof under tension during its workin stroke. IPA machine tool having a longitudinal cutter bar with a plurality of longitudinally spaced cutters thereon, and means for automatically subjecting said bar to substantially a uniform stress throughout its length during the entire working thereof and as long as the texture of the material being worked is uniform. 8. In a broaching machine, a broach adapted to do a unit of work, and means for subjecting said broaoh to a working stress less than the total force required for performingsaid unit of work, said means being operable in either direction of movement of cally prevent at least a part of said means from further affecting said broach includ ing means for placing a portion of said' broaoh under compression and another portion thereof under tension during its working stroke.

10. A broaching machine comprising a broach, and hydraulically operated means adapted to maintain a workin stress throughout the length of said broach during its entire 'workingstroke and adapted upon completion of said stroke to prevent at least a part of said means from further affecting said broach.

11. A broaching machine comprising a broach, and means for simultaneously imparting substantially equal forces acting in the same direction to the opposite endsof the broach throughout the working stroke of the latter.

12. In a broaching machine, a broach, and'means for automatically transmitting a substantially equal push to one end of the broach and pull to the other end thereof throughout its working stroke.

13. In a broaching machine,means for simultaneously pushing and pulling a broach, and means for dividing automatically the power so that the push and pull will be substantially equal throughout the working stroke of the broach.

14. In a broaching machine, a pair of alined cylinders, pistons therein, means for operatively connecting one end of the broach to one of said pistons, means for operatively connecting the other endof said broach to the other of said pistons, and means. for simultaneously moving said pistons in one direction.

15. In a broaching machine, means for applying a pull to one end of the broach and simultaneously pressure to the other end 17. In a broaching machine, a broach, and

means for reciprocating the same comprising pistons operatively engaged one with each end of said broach and means for subjecting said pistons 'to fluid pressure whereby said broach may be subjected to substantially equal unidirectional pushes and pulls.

18. In a broaching machine, a broach, and means for reciprocating the same comprising a piston adapted to push the rear end of said broach, and a piston connected to the forward end of. said broach and operative to transmit a pull thereto, said pistons being of substantially equal areas.

- 19.- In a broaching machine, a pair of coaxially disposed cylinders, a Work abutment member disposed between said cylinders, pistons in said cylinders having piston rods directed toward said abutment, means for connecting an end of a broach to either of said rods and for transmitting the force of the other to the other end of such broach, and manually controlled means for supplying and exhausting fluid cooperating with said cylinders. 20. In a broaching machine,a broach, a pair of alined cylinders, pistons therein, rods connected to said pistons, means carried by said rodsand adapted to operativelyengage said broach, said pistons being relatively movablewhereby said means may engage said broach at the opposite ends thereof, and means for subjecting said pistons to equal pressures.

21In a broaching 'machineja broach, a

pair of alined cylinders, pistons therein,

rods connected to said pistons, means carried by said rods and adapted to operatively engage said broach, said pistons when said means are in engagement with said broach occupying different relative positions in their cylinders, and means for subjecting said pistons to equal pressures.

22. In a broaching'machine, a broach, and alined power means each having amenaber which is adapted to operatively engage an end of said broach and cooperatin in moving the latter through the work piece,

said memberswhen said power means are in initial position being spaced apart a d1sdance greater than the length of the broach, and said power meansoperating automati- 'cally to cause approach between said memiforces.

25. In a broaching machine, a broach,- and meansincluding reciprocable elements menace herstd talre place at the beginning of the I broac'hing operation whereby both will contact withthe broach, and said members thereafter moving together in engagement with the broach until the conclusion of the broa'ching operation! 23. In a broaching machine, a broach,

alined power means each having a member which is adapted to operatively engage an end of said broach and cooperating in moving the latter through the worlr piece, said members when-said power means are in initial position being spaced apart a distance greater than the length of the broach, and said power means operating automatically to cause approach between said members totake place at the beginning of the broaching operation whereby both will contact with 'the broach, and said members thereafter moving together in engagement with the pistons to fluid pressure whereby said' broach may be subjected to substantially equal unidirectional pushing and pulling one engaging each end of said broach whereby the latter may be automatically subjected to substantially equal unidirectional pushing and pulling forces throughout its work ing stroke.

' 26. In a broaching machine, a broach, and fluid pressure operated means for reciprocating the same operatively engaged with said broach at each end thereof whereby the broach ma equal unidirectional pushing and pulling forces throughout its workingstroke.

27. In a breaching machine. a broach, and

' independently controllable fluid pressure operated meansfor reciprocating the same operatively engaged with, said broach at each end thereof whereby the broach may be subjected to substantially equal unidirectional pushing and pulling forces.

28. In a broaching machine, a broach, and a plurality of independently controllable fluid pressure operated means acting on said broach for forcing the same through the 'worlr.

29. In a broaching machine, aoneway broach, hydraulically operated means for reciprocating the same with a substantially uniform driving force, and means for sup.

be subjectedto substantially till porting said broach in said broach reciprocating means whereby a cut may be made on each movement thereof.

30. A broaching machine comprising a breach, fluid pressure operated means for subjecting one end of said breach to a working stress less than the total force required to force the breach through the work, and means for subjecting the other end of the broach throughout the stroke thereof to a substantially equal force, the combined action of said forces being sufficient to force the broach through the work.

31. A broaching machine comprising a broach, and fluid pressure operated means for imparting substantially equal forces acting inthe same direction to the opposite ends of the broach throughout the working stroke of the latter.

32. A. broaching machine comprising a breach, and fluid pressure operated means for simultaneously imparting substantially equal forces acting in the same direction to the opposite ends of the broach throughout the working stroke of the latter.

33. A broaching machine comprising a broach, means for pushing said breach, means'for pulling said broach, and means interconnected to said pushing and pulling means for automatically maintaining. the pushing and pulling forces on said broach substantially equal. 1

34. In a broaching machine, a broach, fluid pressure operated means for pushing said broach, fluid pressure operated means for pulling said broach, and means having fluid connections with said pushing and pulling means for automatically maintaining the pushing and pulling forces on the broach substantially equal.

35. A broaching machine comprising a broach, fluid pressure means for pushing said broach, fluid pressure means for pulling said broach, means for independently controlling said pushing and pulling means,

and means having fluid connections with said pushing and pulling means for automatically maintaining the pushing and pulling forces on the broach substantially equal.

36. In a broaching machine, a broaching tool, and means for actuating said tool including a plurality of cooperating simultaneously operable hydrauliccylin ers' and pistons.

37. In a broaching machine, a broaching tool, and means for actuating said tool including a plurality of cooperating hydraulic cylinders and pistons, said .p1st0ns being simultaneously" movable in the same direction.

38. In a breaching machine, a breaching tool, means for actuating said tool including a pluralit of cooperating simultaneously operable ydraulic cylinders and pistons,

means whereby the pressure on each of ing hydraulic cylinders and pistons, each of said pistons being crosshead.

40. In a breaching machine, a broaching tool, a crosshead having means for connection with said tool, and means for actuating said tool including a plurality of cooperating hydraulic cylinders and pistons, each of said pistons being adapted either independently or simultaneously to move said crosshead.

41. In a broaching machine, a broaching tool, means for actuating said tool including a plurality of cooperating simultaneously operable hydraulic cylinders and pistons, and means whereby the pressure on each of said pistons is substantially the same during at least one movement thereof, the combined displacement of said pistons in one direction of movement being substantially equal to the combined displacement in the opposite direction of movement during the actual working portion of their stroke.

42. In a breaching machine, a member having means for connection with a broaching tool, and--a plurality of simultaneously operable hydraulic cylinders and pistons for actuating the same, said istons and cylinders being so constructs and arranged adapted to move said that the fluid displaced during the actual during one of said movements.

44. In a breaching machine, a member having means for connection with a broaching tool, a plurality of hydraulic cylinders with pistons therein having piston rods projecting through an end of each of said cylinders, and means for alternately subjecting opp'losite sides'of at least one of said pistons to ydraulic pressure during opposite movements thereo while at least is e piston rod end of the other of said pistons is also subjected to hydraulic pressure durin one of said movements, said cylinders an pistons being so constructed and arranged that the fluid displaced in either direction of move ment of said pistons and during the workin stroke thereof is substantially a constant v0 ume.

45. A broaching machine comprising a broach, and hydraulically operated means for simultaneously imparting substantially equal forces acting in the same direction to the opposite ends of the broach throughout the Working stroke of the latter.

46. In a broaching machine, a broach, and hydraulically operated means for automatically simultaneously transmitting a substantially equal push to one end of the broach and pull to the other end thereof throughout its working stroke. a

47. A broacliing machine comprising a broach, and hydraulically operated means In testimony whereof I aflix my signature.

OM'ER J. DANSEREAU. 

